This invention relates generally to portable tanks and more particularly to a sloped bottom structure of a portable tank adapted for liquid storage and transport.
A large tank for liquid storage generally has a bottom discharge. Construction of a tank having a bottom discharge generally requires affixing legs to the bottom of the tank so as to raise the discharge opening from the ground or the supporting surface on which the tank rests. In order to provide complete drainage of tank contents, either a rounded bottom is provided with a central discharge opening or a side discharge is provided by having internal baffles welded inside the tank to provide an internal surface sloping towards the discharge opening. This latter approach is preferred because discharge connections must be externally made.
It is more convenient to connect hoses, fittings from the side of the bottom rather than trying to reach a central discharge underneath the bottom of a large tank or bin. However, conventional side discharge construction, requiring baffles, does not lend itself to thorough cleaning of the interior surfaces of the tank because of the difficulty of cleaning tank contents from internal crevices created by the baffles. Material deposits tends to accumulate and concentrate in these crevices. These deposits in turn lead to cracking which results in leakage of the tank contents.
It is an object of the present invention to provide a portable tank having a sloped bottom structure that presents a smooth interior surface sloped toward the discharge opening to allow full drainage from the tank.
It is another object of the present invention to provide a portable tank having a sloped internal bottom surface which requires no internal baffles.
A portable tank having a sloped bottom structure according to the present invention has a generally rectangular bottom plate having a discharge opening therethrough. At least two shallow creases or bends directed toward the bottom discharge opening in the plate form the sloped inner surface of the bottom. The sides of the generally rectangular bottom plate are upwardly curved so as to merge with upwardly extending wall portions of the plate which terminate in a substantially horizontal edge. This edge joins with the vertical sidewalls of the tank.
The bottom structure has four feet, each positioned adjacent a corner of the generally rectangular bottom plate. These feet are hollow elliptical cylinders and may be formed from sheet metal stock. Each foot has a horizontal bottom edge and a sculptured upper edge which is contoured to match the curvature of the bottom plate. The feet position the discharge opening at the lowest elevation of the bottom plate when the feet rests on a horizontal surface.
The upper edges of the feet are sculptured to merge with the curved surface of the tank bottom and position the edge of the bottom plate in a horizontal plane when the bottom edges of the feet are positioned in a horizontal plane.
Further objects, features, and advantages of the invention will become evident from a consideration of the following detailed description when taken in conjunction with the accompanying drawings and the appended claims.